Rooftop AC unit Low-poly 3D model is available on CGTrader for $2. Original author: mdstudios. Specs: 20052 polys, 20855 verts.
BLEND (Blender, filesize: 382 KB), OBJ (OBJ, filesize: 446 KB), FBX (Autodesk FBX, filesize: 590 KB), STL (Stereolithography, filesize: 583 KB)